Spontaneous dimerization and leucine-zipper induced activation of the recombinant catalytic domain of a new adenylyl cyclase of Trypanosoma brucei, GRESAG4.4B

Naula, C. , Schaub, R., Leech, V., Melville, S. and Seebeck, T. (2001) Spontaneous dimerization and leucine-zipper induced activation of the recombinant catalytic domain of a new adenylyl cyclase of Trypanosoma brucei, GRESAG4.4B. Molecular and Biochemical Parasitology, 112(1), pp. 19-28. (doi: 10.1016/s0166-6851(00)00338-8) (PMID:11166383)

Abstract

In this study, we describe the isolation and characterization of a new adenylyl cyclase from Trypanosoma brucei and its activation by dimerization of the catalytic domain. In agreement with the current nomenclature of trypanosomal adenylyl cyclases, this new gene is termed GRESAG4.4B. The complete ORF of the GRESAG4.4B gene encodes a protein of 1291 amino acids. Its predicted protein structure is consistent with the structure of other trypanosomal cyclases, and with the cyclases of L. donovani. GRESAG 4.4B is constitutively expressed during the life cycle of trypanosomes. GRESAG4.4B is a member of a gene family, which contains at least six members, which are all clustered on chromosome IV. The catalytic domain of GRESAG4.4B is able to dimerize spontaneously. However, these spontaneously formed, stable dimers only show minimal enzymatic activity. The addition of a leucine zipper (LZ) derived from the S. cerevisiae GCN 4 gene to the N-terminus of the catalytic domain of GRESAG4.4B strongly activated its enzymatic activity. The LZ appears to enforce a distinct conformation of the dimer, which leads to an increased enzymatic activity, and thus may mimic the effect of ligand-induced dimerization of adenylyl cyclase in vivo.

• Item Type: Articles
• Additional Information: This work was supported by grant 3100–046760 of the Swiss National Science Foundation, grant C98.0060 of COST program B9, and by the UNDP/World Bank/ WHO Special Programme for Research and Training in Tropical Diseases.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Naula, Dr Christina
• Authors: Naula, C., Schaub, R., Leech, V., Melville, S., and Seebeck, T.
• College/School: College of Medical Veterinary and Life Sciences
• Journal Name: Molecular and Biochemical Parasitology
• Publisher: Elsevier
• ISSN: 0166-6851
• ISSN (Online): 1872-9428
• Published Online: 02 February 2001